Notopterus Chitala Research Articles

Molecular cloning of preproinsulin cDNAs from several osteoglossomorphs and a cyprinid

Several preproinsulin cDNAs were isolated and characterized from four members of the Osteoglossomorpha (an ancient teleost group); Osteoglossum bicirrhosum (arawana), Pantodon buchholzi (butterfly fish), Notopterus chitala (feather fin knife fish), Hiodon alosoides (goldeye) and Gnathonemus petersii (elephantnose). In addition, we isolated and characterized the preproinsulin cDNA from Catostomus commersoni (white sucker, as a representative of a generalized teleost). The comparative analysis of the sequences revealed conservation of the cystine residues known to be involved in the formation of the disulfide bridges, as well as residues involved in the hexamer formation, except for B-17 in the butterfly fish, the arawana and the goldeye. However, the N-terminus of the B-chain was very weakly conserved among the species studied. Residues known to be significant for maintaining receptor-binding conformation and those known to comprise the receptor-binding domain were all conserved, except for a conservative substitution at B13, aspartate substituted glutamate in the arawana, goldeye, butterfly fish and white sucker, and at B16, phenylalanine substituted tyrosine in the elephantnose. Phylogenetic analysis of the sequences revealed a monophyletic grouping of the osteoglossomorphs, and showed that they were not the most basal living teleost. Comparative sequence analysis of preproinsulins among the osteoglossomorphs was useful in assessment of intergroup relationship, relating elephantnose with the feather fin knife fish and the arawana, butterfly fish, and goldeye. This arrangement of species is consistent with relationships based on other more classical parameters, except for the goldeye which was assessed as being sister to all the osteoglossomorphs. The white sucker was grouped with the common carp and both are cyprinids.

Ultrastructure and Immunocytochemistry of the Islet Organ of Osteoglossomorpha (Teleostei)

Both routine electron microscopy and immunocytochemistry with protein A–gold were used to identify the cell types within the islet organs of four species of teleosts (Osteoglossum bicirrhosum, Pantodon buchholzi, Notopterus chitala, and Gnathonemus petersii) within Osteoglossomorpha, a subdivision with an ancient lineage. Four primary endocrine cell types, A, B, D, and F, were identified within the islets of the four species examined. The B- and D-cells were located mainly in the central core of the islet in the four species. In general, the A-cells were located at the islet periphery in all of the four species but in P. buchholzi and N. chitala they were also differently distributed toward the islet core. F-cells were present only at the islet periphery. Granules of B-cells in three species had a relatively homogeneous shape of the matrix core, but in O. bicirrhosum, the shape varied greatly. Variation in matrix shape of B-cell granules may indicate a different conformation of insulin molecules among at least some species of osteoglossomorphs, and this observation may have some taxonomic significance. Two somatostatin-containing (SST) D-cell types (D1 and DX) with granules of different shape were observed in all four species of osteoglossomorphs. The granules of the two D-cells immunostained either with anti-SST-25 and anti-SST-14 (D1-cells) or with anti-SST-34 (DX-cells). Immunocytochemistry confirmed that A-cells, containing glucagon-family peptides, and F-cells, containing peptides of the pancreatic polypeptide family, had granules of different shape. The cells of the islet organs of these osteoglossomorphs are more similar to those in more derived teleosts than they are to those of nonteleost actinopterygians.

Angiotensin-converting enzyme in organs of air-breathing fish

Angiotensin-converting enzyme (ACE) was measured in tissue homogenates trom the African lungfish and six species of air-breathing teleosts ( Heteropneustes fossilis, Clarias batrachus, Channa gachua, Anabas testudineus, Notopterus chitala, and Monopterus cuchia) using a standard apectrophotometric assay. In most species, the highest levels of ACE activity were found in the respiratory organs (gills and/or accessory respiratory organs). ACE was also found in heart and kidney tissues from most species and occasionally in liver. Converting enzyme was not found in skin or skeletal muscle from any species and only in blood from H. fossilis and brain from C. batrachus. Captopril, a potent inhibitor of mammalian ACE, inhibited enzymatic activity from all tissues except C. gachua heart and liver and A. testudineus heart. As fish make the transition from aquatic to aerial respiration the gill microcirculation is usually reduced in size and the accessory respiratory organs become elaborated and occupy a more central position in the vascular tree. The presence of ACE in accessory respiratory organs of air-breathing fish appears to greatly enhance the metabolic efficiency of this enzyme on circulating substrates.

Bimodal oxygen uptake in a freshwater air-breathing fish,Notopterus chitala

Measurements of bimodal oxygen uptake have been made in a freshwater air-breathing fish,Notopterus chitala at 29.0±1(S.D.)°C. xhe mean oxygen uptake from continuously flowing water without any access to air, was found to be 3.58±0.37 (S.E.) ml O2 · h−1 and 56.84+4.29 (S.E.) ml O2 · kg−1 · h−1 for a fish weighing 66.92 + 11.27 (S.E.) g body weight. In still water with access to air, the mean oxygen uptake through the gills were recorded to be 2.49 ± 0.31 (S.E.) ml O2 · h−1 and 38.78 ± 1.92 (S.E.) ml O2 · kg−1 · h−1 and through the accessory respiratory organs (swim-bladder) 6.04±0.87 (S.E.) ml O2 · h−1 and 92.32±2.91 (S.E.) ml O2 · kg−1 · h−1 for a fish averaging 66.92±11.27 (S.E.) g. Out of the total oxygen uptake (131.10 ml O2 · kg−1 · h−1), about 70% was obtained through the aerial route and the remainder 30% through the gills.

Auditory sensitivity and psychophysical tuning curves in the elephant nose fish,Gnathonemus petersii

Hearing sensitivity and psychophysical tuning curves were determined for the mormyridGnathonemus petersii. Pure tone hearing thresholds were determined from 100 Hz to 2,500 Hz, with best sensitivity being about −31 dB (re: 1 dyne/ cm2) from 300 Hz to 1,000 Hz. In order to determine frequency tuning of the auditory system, psychophysical tuning curves (PTC's) were measured with the masker presented simultaneously with, or just ahead of, the 500 Hz test signal. The sound level for different frequencies needed to just mask the test tone were determined from 100 to 800 Hz. Maximum masking occurred in both forward and simultaneous conditions when the masker and the test tone were at the same frequency. As the masker was moved in frequency from 500 Hz, higher sound levels of maskers were needed to afford masking of the test tone. The data were similar in simultaneous and forward masking, with theQ 10 dB, a measure of sharpness of tuning, being about 5 in both cases. Data were compared for other species for which behavioral thresholds and PTC's are available.Gnathonemus hears about as wide a range of frequencies as the goldfish,Carassius auratus, although the PTC's for the two species are strikingly different. The PTC's forGnathonemus resemble those determined in a forward-masking paradigm for the clown knife fish,Notopterus chitala, even thoughGnathonemus has a wider hearing bandwidth.

Structure and Function of the Auditory System in the Clown Knifefish,Notopterus Chitala

ABSTRACTHearing sensitivity and the anatomy of the auditory system in the clown knifefish, Notopterus chitala, were studied using behavioural techniques and scanning electron microscopy. While many structural features of the inner ear were similar to those found in other teleost species, the saccular endorgan in Notopterus was unusual in having three discrete epithelial regions. These regions could be distinguished from one another by regional differences in portions of the otolith overlaying them, by hair-cell orientation patterns, and by their position relative to the swimbladder. Notopterus was found to be able to detect sounds from 100 to 1000 Hz and best sensitivity occurred at 500 Hz, where the mean threshold was – 30 dB (re : 1 microbar). For frequencies from 300 to 700 Hz there was substantial variation in threshold values and indications of a bimodal distribution of thresholds. One hypothesis that may tie the ultrastructural and behavioural results together is that the ear in Notopterus is anatomically and functionally differentiated to mediate independent detection of two sound properties: changes in pressure and particle motion.

Comparative frequency selectivity in fishes: Simultaneously and forward-masked psychophysical tuning curves

Behavioral methods were used to determine psychophysical tuning curves for three teleostean fish species (Notopterus chitala, Adioryx xantherythrus, and Osteoglossum bicirrhosum) for 300- and 500-Hz signals. Simultaneous masking techniques revealed that 300-Hz curves were similar for all species, with peak masking occurring when the frequency of the masker equaled 300 Hz. In contrast, there were considerable interspecific differences in simultaneously masked 500-Hz curves. The 500-Hz curve for Adioryx was a broadly tuned, V-shaped function with peak masking occurring in the frequency region of the signal, whereas the curve for Notopterus was a sharply tuned, multipeaked function with peak masking occurring for both 500- and 300-Hz maskers. Comparisons of tuning curves obtained with both forward and simultaneous masking techniques for Notopterus revealed little or no difference between 300-Hz curves, but substantial differences between the 500-Hz curves. These results suggest that there are interspecific and frequency-dependent differences in the frequency selective processes of fish auditory systems.

Host range of Achlya prolifera (Nees) de bary on certain fresh water teleosts

Host range of Achlya prolifera (Nees) De Bary has been extended to Cotisa fasciatus, Colisa lalia, Puntius sophore, Notopterus chitala, and Anabas testudineus by conducting artificial inoculation experiments under controlled laboratory conditions.

Studies on the Pollution of the Kalinadi by Industrial Wastes near Mansurpur Part 2: Biological Index of Pollution and Biological Characteristics of the River

AbstractFrom the biological data presented here it is difficult to define any species of fish as an indicator of pollution in the strict sense. Nevertheless, the following generalizations are possible. ‐ Species as Wallago attu, Clarias batrachus, Heteropneustes fossilis, Ophiocephalus striatus and Oph. punctatus occur in good number in the polluted stretch and seem to be tolerant species. ‐ The species as Esomus danrica, Labeo rohita, Labeo gonius, L. bata, Catla catla, Cirrhina mrigala, Barbus chagunio, Barbus spec., Notopterus notopterus and Mugil corsula are most sensitive and disappear first in the polluted stretch. ‐ The species as Barilius bola, B. bendelisis, Nemacheilus latius, Notopterus chitala, Collichrous bimaculatus, and Nandus nandus are moderately sensitive. ‐ It appears that the main damage is caused to carp and feather‐back fishes. The whole stretch of heavy pollution is almost devoid of carp and featherback. The following important conclusions can be drawn from the distribution of plankton and bottom organisms: ‐ The higher number of protozoans, chironomids, maggots and the decrease in the number of mollusca can be considered as the indicator of pollution, because of their abundance in polluted zones. ‐ Chlorella, Lyngbya, Gyrosigma and Euglena (algae), Viviparius (mollusc) and Bosmina (crustacea) are very sensitive to pollution. ‐ Oscillatoria, Pandorina, Anabaena, Nitzschia, Closterium (algae), Branchionus, Rotatoria (rotifers) and Naidium (annelid) are moderately sensitive. ‐ Synedra, Spirogyra, Desmidium, Rivularia, Navicula, Fragillaria Phacus, Arcella and Vorticella are fairly tolerant forms. The stretch studied has been subdivided into five zones with characteristic features: ‐ The Oligosaprobic Zone ‐ characterized by a sufficient oxygen saturation, low B. O. D. and C. O. D., with a good fauna and flora. ‐ The Polysaprobic Zone ‐ with low oxygen saturation, high B. O. D. and C. O. D. and hydrogen sulphides with a restricted fauna and flora. ‐ The α‐Mesosaprobic zone ‐ with moderate oxygen saturation, moderate B. O. D. and C. O. D. traces of hydrogen sulphide with the improvement of the fauna and flora. ‐ The β‐Mesosaprobic Zone ‐ with fair oxygen saturation, low B. O. D. and C. O. D., with the reappearence of fauna and flora. ‐ The Oligosaprobic Zone ‐ similar to the zone of low pollution in all characteristics.

Karyotype studies in the genus Notopterus (Lacepede). The occurrence and fate of univalent chromosomes in spermatocytes of N. chitala.

The present report is based on the karyotype studies of two species of fishes,Notopterus chitala andN. notopterus, collected from the river Jumna, Delhi, India. Both species possess a diploid number of 48 chromosomes, 12 of which are metacentric. The primary and secondary spermatocytes of one individual ofN. chitala have been found to possess varying numbers of univalent chromosomes. The possible origin and fate of the univalents are discussed.

The histochemistry of the saccus vasculosos of Notopterus chitala (Teleostei)

ABSTRACT The saccus vasculosus of Notopterus chitala is situated posteriorly to the pituitary gland. It consists of a number of loculi surrounded by blood sinusoids. The loculi open into a number of collecting channels which unite and ultimately drain into the third ventricle of the brain. The loculi are lined by a layer of pear-shaped ‘coronet cells’. The coronet cell has an apical protrusion provided with hairs, each ending in a globule. The coronet cells contain glycogen, especially in the apical protrusions and in the globules. Phospholipid, alkaline phosphatase, and mitochondria are concentrated in the apical protrusion and globules. There are also mitochondria round the nucleus. The Golgi element is not only present in the characteristic Golgi zone but occasionally round the nucleus as well. It has been stated by other authors that acid mucopolysaccharides are synthesized in the coronet cells of the rainbow trout and ‘secreted’ into the lumen of saccus vasculosus. However, acid mucopolysaccharides are not histochemically demonstrable in the coronet cells of Notopterus. The observations recorded in this paper indicate that the coronet cells in the saccus vasculosus of Notopterus are secretory and that glycogen is abundant in them.

The histophysiology of the saccus vasculosus of Notopterus chitala (Teleostei)

ABSTRACT The apical protrusions of the coronet cells of the saccus vasculosus in Notopterus chitala contain glycogen which passes through the hairs into the globules. In spite of the availability of normal blood-glucose levels in fed controls, only a few cells in the loculi show glycogen ; thus there are individual differences in the physiological activity of the cells. Specific variations in the distribution of glycogen in the different parts of the coronet cells were observed under conditions of starvation and glucose adminis- tration. Starvation for 48 h resulted in depletion of glycogen unidirectionally from the apical protrusion towards the globules. Fish starved for 46, 44, and 42 h were injected intraperitoneally 20% glucose (2 g of glucose per kg of body-weight) and autopsied 2, 4, and 6 h respectively after glucose administration. Comparison of the results obtained with starved fish injected with glucose suggests the gradual conver- sion of blood-glucose into glycogen. This conversion appears to begin at the base of the cell-body and to move towards the apical protrusion. The saccus vasculosus in Notopterus chitala is possibly a source of glucose for the cerebrospinal fluid.

Respiratory Function of the Swim-bladder of Notopterus (Lacepede)

BRIDGE1, working on the swim-bladder of Notopterus borneensis (Bleeker), and Srivastava2, on that of Notopterus chitala (Buchanan-Hamilton), concentrated their attention only on the general plan of the organ.